LibraryLab5.quickSort()
because the method requires a parameter, did you intend for the previous line to be used as a parameter?

list.compareTo(tArray)
list is an array... don't think you can call a class method on an array like this. the comment next to the class definition suggests that it should implement comparable, and to take a look at how to use it in your textbook.

What don't you get? What logic are you having trouble conceptualizing? Simply posting your code and asking somebody the explain it is not the way it works. What are your errors? Where are the errors? What IDE (Integrated Development Environment) are you using? Explain what you are trying to do and what steps you have taken to complete them. What specific steps are you having trouble with?